attacked unsuccessfully again on 30 May suffering 1 killed and 45 wounded. The PAVN abandoned the hill during the night of 30/31 May. Operation Prairie IV resulted in US claiming 505 PAVN killed and 8 captured for 164 Marines killed and 1240 wounded. Operation Cimarron Operation Cimarron began on 1 June in the same area with the same units. There was limited contact with the PAVN but many enemy bunkers and supply caches were found and destroyed and several PAVN graves located. Cimarron ended on 2 July. On 1 July the land-clearing project from Con Thien to Gio Linh was completed, with the clear strip widened to 600m. Operation Buffalo On 2 July Companies A and B from 1/9 launched Operation Buffalo, a sweep of the area north of Con Thien. As the infantrymen moved along Route 561 in an area called the "Marketplace" (), the PAVN attacked, inflicting severe casualties on Company B. This was the single worst day for the Marines in Vietnam (86 killed). Operation Buffalo concluded on 14 July at a cost of 159 Marines killed and 345 wounded. The PAVN were claimed by US sources to have suffered 1290 killed. Operation Hickory II Following the conclusion of Operation Buffalo, III MAF ordered a sweep of the southern half of the DMZ. Operation Hickory II lasted from 14–16 July and resulted in 39 PAVN killed for the loss of 4 Marines dead and 90 wounded. During July the Army transferred Con Thien to the Marines. Operation Kingfisher Operation Kingfisher took place from 16 July to 31 October 1967. Operation Kentucky Operation Kentucky took place from 1 November 1967 to 28 February 1969 and resulted in 520 Marines killed and 2698 wounded, while US reports claim the PAVN lost 3,839 killed, 117 captured and an unknown number wounded. In support of Operation Kentucky, squadrons of the First Marine Air Wing provided air support from 4 January 1968 to 23 March 1968. Air support missions included resupply of ammunition, rations, and other supplies. Numerous medevac missions were flown to transport wounded Marines to medical facilities at Dong Ha and to the hospital ship Repose. Bombardment In September 1967 the PAVN started their major shelling of the base hitting it with at least 200 artillery and mortar rounds daily, peaking on 25 September when a reported 1200 rounds hit the base. From 19–27 September more than 3000 rounds hit